


Demon's Blood On My Hands

by Misc_ed (Thorki_ed), Thorki_ed



Category: demon slayer - Fandom, 鬼滅の刃 | Demon Slayer: Kimetsu no Yaiba (Anime)
Genre: Alternate Universe - Modern Setting, Consensual Sex, Dom/sub Undertones, Drug Use, F/F, F/M, Gang Violence, Gen, Giyuu has a big dick FIGHT ME, M/M, Multi, Murder, Non-Consensual Drug Use, OUR BOI IS BIG ON CONSENT, Other, Praise Kink, Slow Build, Stockholm Syndrome, Violence, more tags as I go along, swords become guns
Language: English
Status: In-Progress
Published: 2021-02-10
Updated: 2021-02-22
Packaged: 2021-03-16 02:48:00
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 3
Words: 5,054
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29324949
Author URL: https://archiveofourown.org/users/Thorki_ed/pseuds/Misc_ed, https://archiveofourown.org/users/Thorki_ed/pseuds/Thorki_ed
Summary: You never imagined your life would be like this - lost, alone and broken. Muzan Kibutsuji found you orphaned in a hospital and promised you a home. Giyu Tomioka found you and promised you a life.Come join me on Tumblr! https://absolutegiyuuslut.tumblr.com/
Relationships: Tomioka Giyuu/Original Female Character(s), Tomioka Giyuu/Reader
Comments: 3
Kudos: 26





	1. Thirteen

**Author's Note:**

> This turned out much darker than I intended, but I am now invested. Between two jobs, my updates may be slow, but I promise to pour my whole soul into it. 
> 
> I made it a Reader Insert, but I didn't leave every characteristic blank - please sub along the way, darling!

Muzan had picked you up just days after your family, and most of your neighbourhood had been slaughtered. You didn’t remember much from the night - just screams, darkness and the smell of death. A gang war, they said. The hospital you woke up in was the opposite - bright lights and white walls, and the only sound was the beeping noise to indicate you were still alive. They said it’d been a miracle that you were alive and you were lucky, but you never felt that way. Before you could panic about where you would go, a staff member had said a man by the name of Muzan Kibutsuji had heard about the tragedy and wanted to help you. 

You’d never met this man in your life, but his eyes were bright and beautiful. He smiled at you and said that you didn’t deserve to be all alone in this cruel and unforgiving world. He said you’d have a home with him.

“You can call me Muzan, little one. What shall I call you?”

“My name is [y/n].”

“How pretty,” he cooed. “Would you like to come home with me?”

Home. You’d been stuck on that word for a while. You didn’t have anywhere else to go, did you? So you said yes, and when he smiled proudly at you, you felt a warmth you couldn’t explain. 

“Thirteen!” He called. You quickly jumped up, hair only half brushed and rushed to the next room, where he waited for you. 

“Yes, Master?” You bowed upon entering. 

“Someone has requested you tonight,” he said in that cool, even tone of his. 

“Me?” You asked in surprise. You were partly surprised, and felt a moment of joy that you could finally prove yourself useful to him, but then fear quickly took over. If this new customer was anything like the previous ones, you winced at what could await you.

“Yes. This is a very special mission, Thirteen. I hope you do not fail me.” His voice seemed to freeze over with the last sentence, and you knew for a fact that whatever this customer wanted to do to you - it was not nearly as bad as what your Master would do to you if you were not satisfactory.

“I won’t, Master,” you vowed, trying to keep the tremble from your voice.

“Good. He’s just outside our district, Thirteen. A business mogul and a lawyer. Not only is he rich, but powerful as well. His name is Giyu Tomioka. We want to make sure he is a returning customer,” he stressed. 

Out of district? That was rare. He kept his customers under close eye - everyone in this district knew of Muzan Kibutsuji. Though they knew him by the name Demon of the Night. None of their customers had ever laid an eye on him, and you knew there were all sorts of rumours and speculation surrounding his identity. It was this fear and mystery that kept all their customers in line, just like how Muzan wanted. So now that you knew you would be just outside his domain, you were even more worried. Muzan was powerful - perhaps the most powerful man you’d ever lay eyes on, but even he had boundaries and borders he couldn’t reach. 

“I won’t let you down, Master.”

“Good,” he gave you a thin smile. “Go get dolled up, then. I hear his favourite colour is blue.”

\-----------------------

When the drive dropped you off outside a big business building, you were confused. Simple but bold, it read “Urokodaki Legal Profession Corporation”. Muzan prided himself on being a very discreet man, protecting the identities of his customers. The scandal that would break out if you were to waltz into the front door of this business building would be humiliating for everyone. Still, the driver turned into the alleyway next to the building, where there were no lights on. He came to open your door, and as you stepped out, you looked around. There were people walking up and down the street - anyone could see you, if they looked. But they all seemed to pass without a second glance down the alleyway, absorbed in their own matters. You took a timid step towards the door, unsure of yourself, before the driver grabbed your elbow and guided you further down the alley. Though it wasn’t cold weather, the breeze made you shiver just slightly. You came to a back door that had been propped open by a small brick. 

“Top floor,” the driver grunted before turning back to the car. You opened the door, revealing a dimly lit corridor and nudged the brick inside with your foot so the door could close properly. There was a lift to your right and a door to your left. When you opened the door, you only saw stairs that went up and up. You’d never reach the top floor that way. 

Lift it is, then. 

It was a confined little space, and you pressed the furthest button at the top “PH2”. While the lift rattled as it went up, your heartbeat was louder. You swallowed thickly but couldn’t help shaking - no blaming the weather this time. When the soft ding came and the doors opened, there was only one door in front you. You steeled yourself for what was to come taking deep breaths before summoning all your courage to knock on the deep red doors. 

A buzzing noise and click indicated that the door was unlocked. 

Your clammy palm wrapped around the brass handle and pulled, opening the doors in front of you. You hadn’t expected the sight that greeted you on the other side.


	2. Chapter 2

It was a large office space, minimalistic with sparse furniture and mostly black, or steel decor. The only hints of colour were the deep red leather of his seating, and a peculiar green and yellow pattern mantlepiece that stood on the shelf above his fireplace. A large wooden desk held three computer screens and mountains of papers, neatly stacked on either side of him.

The man behind the desk was just as orderly and neat as the office - the only thing remotely out of control was his long, black hair. He didn’t seem surprised to see you, and didn’t make any move to come to you. You fidgeted for a moment under his intense gaze, but found it so hard to look away. His eyes captivated you immediately, and you lost all idea of what you had to say. Embarrassed, you quickly looked away as you knew it was rude and insubordinate to stare up at the man. 

“Have a seat, I’ll be done soon,” he instructed. He hadn’t specified where, so you made your way to the leather couch opposite of his desk, a comfortable distance away. A glass table in front of you held an assortment of business magazines and newspapers, so you read the covers to keep yourself occupied, trying to steal some glances at the man in front of you. 

He was different from the others already. Your previous customers had been loud, aggressive, and couldn’t wait to throw you in their beds the moment you arrived. This man, Tomioka, radiated a calm energy, and his movements were precise. His hands flew over the keyboard effortlessly as his eyes drifted back and forth between his screens. The light from the computer made his eyes shine unnaturally, but you could see how deeply blue his eyes were. 

After a few moments, he got up from his desk. 

“What is your name?” He asked. 

“Sugar,” you replied automatically. All the girls were called Sugar. Your pictures were all numbered, and you happened to be number 13. That’s how Muzan started to keep track of you. It was obvious that your real name shouldn’t be used, so he didn’t press further, even though he wanted to know. 

“Show yourself to me, please,” he asked politely. You were a little dumbfounded at how gentle he had been so far, but you knew that it could change in an instant. Muzan’s customers all had tempers and they could flip like a switch. You undid your belt, letting the thin haori you were wearing slip off your shoulders, revealing the lacy blue and white lingerie you wore underneath. You let his eyes roam over you, but he still didn’t touch you. 

_Did he want more?_

You began to take the straps off your shoulder before his hand reached out to grab you. You closed your eyes and froze, but nothing happened. You slowly opened them to see his hand had only come out to stop you from moving any further, and he wasn’t hurting you at all. But his eyes were trained on you with an expression you couldn’t quite read. It seemed dark.

“I’m sorry!” You blurted out, because it seemed you had ruined the atmosphere. He straightened out, and retracted his hand, studying you in silence. It made you nervous.

“You’re free to leave, if you’d like.” 

“No, please!” You wailed immediately. A brief look of shock passed across his face before he schooled his features. He wasn’t expecting you to react like that - he thought maybe, you’d be relieved. 

“I - I can do anything you want. Please, just tell me what to do - I can do it, I promise.”

“I’m still paying you for the full time,” he tried to assure you, thinking maybe that’s why you were upset. Your cheeks glowed red with embarrassment as you hugged yourself. _How pitiful you were!_

“He - he’ll know. I can’t go back this early - please, Mr. Tomioka, sir, ask anything of me. I beg you,” you sniffled a bit. 

He clenched his hand - something wasn't right. _She shouldn’t be so terrified of ending a job early._ Still, the way you begged awoke something primal in him, and he would be lying if he said his cock didn’t twitch at the way you said his name. But he couldn’t take advantage of you - especially since something told him that there was more going on. 

“What is your real name?” He asked. You blinked owlishly at him. It was against Muzan’s protocols to give out your real identity, but you also didn’t want this man to get more upset with you and send you away. Then, Muzan would know that you had failed and that would be even worse.

“M - my name is [y/n].”

“[Y/n],” he said softly. You were now at an impasse - neither of you knew what to do or say.

“Do you - would you like to touch me?” You offered, straightening yourself out again so he could take a look at your body again. Once again, he clenched his fists. 

“No, I -” He was interrupted by your immediate sniffling. _Am I so hideous he doesn’t even want to touch me?_

“I’ll do anything you want,” you pleaded one more time. “Anything.” He was now at a loss. He was trying to give you an easy way out but it seemed to be doing even more harm than good. He sighed quietly.

“Help me finish my work then,” he compromised. You looked up at him with surprise, eyes glistening with tears, but you nodded and followed him as he made his way back to the desk. You slipped your haori back on, and wrapped it around yourself, suddenly self-conscious. Even dolled up with lingerie, you couldn’t entice the young man, and your cheeks burned with shame. He didn’t seem to notice as he pulled up a spare chair to his large desk. 

“These are the reports that I need to go through,” he pointed at the smaller pile to his right. 

“I need to look through these numbers here, here and here,” he pointed out various lines before pointing to one of his screens. “They need to match up to this. Once I confirm that they’re the same, this page needs to be reviewed.”

He went on explaining a few basic things, flipping through the report, and pointing at the computer. 

“Do you have much experience with the computer?” You shook your head. Muzan didn’t allow any of you access to his computer, and it was the only one in the house. He hummed at your response - likely out of annoyance. 

“I can do it,” you piped up before he could change his mind. You shuffled your chair closer and took the first report off the stack. He watched you closely as your eyes scanned the page for the numbers he needed and found them quickly on the spreadsheet he had pulled up. Repeating the entire process he just taught you, you reached the last page of the report before you began to worry.

“What happens if… something isn’t right?” You asked timidly. You didn’t want to insult him, or whoever wrote these reports. 

“Where?” His eyebrows furrowed and he opened his hand for you to pass the report.

“Here, on the last page,” you pointed as he took hold of it. His deep blue eyes scanned it, frowned, and flipped back to the beginning. Retracing your steps, he flipped through and compared the numbers for himself. You felt relieved when he pulled out a red pen and circled the incorrect number on the page. 

“That was good work,” he complimented and you beamed at him. Wanting to prove your use further, you quickly grabbed the next report. 

_____________

TOMIOKA:

_The young woman was strange, to say the least. She was scared, that much was obvious. The service was supposed to be a discreet network of businessmen, who had reputations to protect. It wouldn’t do the business good if you were caught with an escort, after all. Yet, he could tell right away she had likely been abused in some way. He had barely moved toward her before she had flinched - it didn’t sit right with him. Yet, he couldn’t turn away after she begged him not to. There must be a punishment for those who don’t complete their assignments._

_And he reminded himself that was all he would be - an assignment. Most days, it was hard not to feel lonely. The people that worked for him - they had family, friends, and always seemed to be smiling and enjoying each other’s company. He didn’t have that. And so, if he had to be just a credit card number to someone, so be it._

_It was different when Sabito was alive, when the two of them shared the responsibilities and rewards of their success. There was a warmth that never returned after Sabito’s passing._

_“Is there… anything else, that I can help you with?” He blinked away an almost-there memory and peered at the woman beside him. Indeed, his stack of reports had dwindled to nothing, save for the last one in her hands. Had he been daydreaming for that long?_

_“Let’s see,” he replied. She was a quick learner, that much was obvious. She had even picked up a red pen at some point and began marking the errors she saw without his guidance. Still, he had only just shown her the process a minute ago. Out of the corner of his eye, he watched her. Her tiptoes barely grazed the floor when she swung her legs lazily beneath her small frame. Her long, inky black hair tumbled over her back and shoulders like a river. He was drawn to her by the soft blue lingerie she wore underneath her haori, but was careful not to let his eyes linger too long. She was... soft. Delicate. Light. Everything he wasn't._

_“Not bad,” he hummed. She looked up at him, with a question in her eyes but it seemed she was too nervous to ask._

_“Four out of fifty isn’t bad," he clarified. "It’s not perfect, but it’s expected. We all make mistakes.”_

_____________

When he said those words, you could hear the weighted sadness behind it. Though you’d just met him, he seemed gentle and kind. He carried a weight of responsibility on him that was about more than just making money. You’d bet he was a kind soul, something in his eyes told you that. It still wasn’t time for you to go, and now you’d started to feel guilty. Though you were relieved that he wasn’t pushing you, you knew that Muzan charged a hefty price. 

“Here, let me help you… relax,” you offered timidly. You knew you weren’t as appealing as Muzan’s other girls, but you knew that your soft demeanour was sought after. Men liked to feel powerful. You stood up and placed your hands on his shoulders, which automatically tensed. 

“I’m sorry, if I startled you,” you whispered as you gently slid your fingers across the tense muscle, applying a pressure. Even through his suit jacket, you could feel that he was well-built and with your much smaller frame, you were sure that he could handle the pressure even if you tried your hardest. He relaxed quite quickly after, the two of you existing in a peaceful silence save for the click-clack of his keys as he continued to work. It seemed he never stopped. Every now and then, you had to grip his shoulders and pull him back as he inched his face closer and closer to the screens. He was going to turn into a hunchback if he kept going like this! You teased him for it lightly, and earned a soft chuckle in response. Clearly, it was not the first time he’d heard it. 

You wondered why he worked so tirelessly. Surely a young, handsome man such as him must have hobbies and friends outside of work? Was he not a wealthy businessman? Could he not hire more help to give himself a break? 

“I believe your time is up.” His voice snapped you out of your thoughts.

“Oh,” you startled, backing away as he stood up. “You haven’t… I mean, I didn’t, um.” 

“It was fine,” he assured you. Though he had kind eyes, it seemed he almost never smiled. It was hard to tell how he truly felt. 

“I’m sorry, I lost track of time, had I known…” He shook his head to stop you. 

“Thank you for your company,” he said softly. “Do you need an escort downstairs?”

“Um, no, I should be okay…” 

It was clear that neither of you really knew what to say or do, but you did take a step toward him and lay a gentle kiss upon his cheek. It would be a shame if he didn’t receive anything from you, after all. 

“I hope you have a good night, Mr. Tomioka,” you bowed before turning to leave. Hopefully, he wouldn’t tell Muzan about your horrible performance - or worse, ask for a refund.


	3. Demon's Blood

When Muzan had asked you how it went, you were flustered. You didn’t want to lie, in case he did complain about you but you didn’t want to tell Muzan you failed either. 

“I… He seemed content, Master, but I’m sure he’ll ask for one of the others next time.”

“I see. Let’s hope you didn’t screw it up too badly,” he said. You shivered at the underlying threat. 

Surprisingly, just five days later, it was Giyu Tomioka who had requested you again. Muzan raised a questioning eyebrow.

“Whatever it is you did last time… Be sure to keep doing it,” he said, dismissing you with a wave of his hand. 

Slowly, you got yourself dressed and put on your makeup. You had another hour before you’d be heading out so you decided to get a snack, at least. As you tiptoed downstairs, you heard voices that you didn’t recognize and froze. Muzan’s voice rang loud and clear. 

“Do not fail me again or it will be the last thing you do.”

“Yes, of course, we won’t fail again. Please, we just need a little more time,” a sniveling voice responded. A deeper, male voice joined in. 

“That’s right, we can be of use to you, I know it. Maybe you could give us a little more Demon’s Blood, we could -“

“Did you just tell me what to do?” Muzan’s chilling voice interrupted. 

“N-no! No, sir. I would never!”

You heard what had to be a gunshot and slapped your hand over your mouth to stop from screaming. 

“If you do not wish to join him, I suggest you bring me my money by tomorrow night. Prove yourself to me, and I will find you a new partner.”

“Yes, sir!” 

You backed away from the stairs as the footsteps began shuffling and caught a glimpse of short, spiked black hair exiting the mansion. Quietly, you rushed back to your room. 

You knew that Muzan did some things that weren’t exactly legal, but you’d never guessed that he was such a cold stone killer. He didn’t hesitate to kill that man! After a few minutes, his slight knocking startled you. Calming yourself, you opened the door and faked a small smile. 

“I’m almost ready,” you said. He glanced at you up and down, nodding his approval. There was no way around it, you knew he came to check on you because of the gunshot, it was so loud the whole mansion would have heard. 

“Are you alright, Master?” You asked in a worried voice. You checked him all over, but you didn’t even find any blood splatter. How odd. 

“Of course I am, why wouldn't I be?”

“I heard a loud banging noise,” you replied. “I was going to come check on you.”

“No need, little one,” he said calmly. “It’s time for you to go now.” You nodded, seeing a dismissal. 

This time, you knew where to go, and the same side door was propped open by the same brick. Even though it was only your second time here, you felt more confident in yourself. As you entered, nothing had changed about the room, and there he sat behind his desk again with his eyes glued to the screen. 

“Mr. Tomioka,” you bowed. 

“Come sit,” he gestured to the chair beside him. Then, his eyes found yours before they travelled down your body, and he looked away quickly. Was that a hint of shyness? Feeling bold, you shrugged your haori off, showing a sky blue crop top with a black leather skirt before taking a seat beside him. Wordlessly, he pushed his stack of reports closer to you and you fell into the same rhythm as last time, remembering every step. Out of the corner of your eye, you could see him glance over at you every now and then. As you finished reviewing the last report and passed it to him, he swallowed thickly, still avoiding eye contact. 

Why did he make you feel so powerful, when you were just a nobody? The white knuckle grip he had on his mouse and the tense grind of his teeth made it seem like he was trying so hard not to touch you - even though that’s what he paid for. You didn’t understand him at all.

“You can look, you know,” you said shyly. “And… touch. If you wish.” You heard him inhale sharply. You could practically feel the mouse crack underneath his hand. 

“That’s… We shouldn’t,” he said, without any explanation. You were a bit surprised at how it seemed to hurt you. Usually, you never wanted to do anything the customers asked, but with him… you almost wanted him to.

“Why do you hire us if… If you don’t want…”

“It’s not always about that,” he murmured, eyes intent on his computer. You let it go, knowing your thoughts were a bit scattered from the earlier encounter you’d overheard. What was Demon’s Blood? Who were those people? How would Muzan escape from this? Did he... always do this? 

Just then, the buzzer rang and Giyu frowned, clearly not expecting anyone. He glanced worriedly at you and with practiced ease, you sank beneath his desk to hide. The buzzer rang again and Giyu had no time to ask you questions. He allowed whoever it was on the other side to enter, tucking his chair in slightly. 

“Sorry, I know you said not to interrupt, but it’s Mr. Rengoku. He said it’s urgent!” The voice sounded a bit winded, like he’d ran all the way here.

“Shit,” Giyu swore under his breath.

“Um, what’s wrong, sir?” 

“Nothing, just - send him up.”

“You got it!” There were footsteps and then the door clicked shut. He quickly reached under his desk for you, and ushered you up to your feet.

“I’m sorry, but I’m going to have to ask you to leave the room. I’d normally ask you to leave entirely but I don’t want to send you back early if…”

“I promise I’ll be quiet,” you assured him, and that seemed enough. He quickly led you to another door and opened it to reveal a bedroom, which surprised you. 

“Would you erm… mind running the water,” he pointed at a joined room. "I’ll be discussing some… confidential matters.” You nodded obediently and made your way to the supposed bathroom. After he heard the tap turn on, he quickly made his way back to his desk in preparation for this impromptu meeting. 

While you wanted to please him, you were also so very curious about the man. The rooms were plain and bare, but elegant. The sink counter and bath had a gorgeous marble design. It was obvious that he was a simple, minimalistic person but the lack of supplies made you believe he didn’t actually live here. There was no extra soap, toothpaste, nothing. Somewhere, he likely had a beautiful home. You knew plenty of men who had more than one place to crash - most of the time, it was to cheat on their spouses or get away from their responsibilities at home. Yet Giyu didn’t wear a ring and had no pictures or indication that he was married. Now that you thought about it, Giyu didn’t seem to have signs of having anyone in his life, and that was a sad thought. Did he stay at the office because there was no one waiting for him? Even if he had no wife, where were his parents? He was so young, after all. 

You peeked out the door and figured you would just take a peek around, that couldn’t hurt right? You could still only hear the running water, after all. Just as you thought, the walls were bare and the room totally devoid of any personal touches. There was a book on the nightstand and you were intrigued as it looked to be a teenage novel. It was in pretty rough shape, like he’d read it numerous times or it’d survived quite a bit of travel. Suddenly, a shout broke your thoughts.

“He’s been **blinded** , Giyu! Blinded. Gyomei will never see again, you know that?” It appeared that Giyu had managed to shush the man but you were surprised. You were under the impression the conversation was related to his work, and this seemed like anything but. You tiptoed closer to the door, knowing it was wrong, but what Giyu didn’t know wouldn’t hurt him, right?

“Left me… charge. We have to.... and move faster… anything…” Even with your ear pressed up against the door and your hand covering your other ear to block out the water, you could only make out a few words.

“What about… Shinobu can…. Right?”

“Working on… Luck...Waiting…” 

“What now?”

“Crack down…tonight's shipment... Demon’s Blood...”

Your eyes widened as you backed away from the door. _Maybe you could give us a little more Demon’s Blood_. That’s what the man had said to Muzan before… Somehow, this was all related! 

You scurried back to the bathroom and closed the door almost all the way. Sitting down on the cold floor, you tried to calm yourself. You didn’t know what it meant, after all, so why were you freaking out like this? Maybe, just maybe, you knew deep down that Muzan was in trouble - or that he was trouble. What exactly did someone like Giyu have to do with this? 

“Sorry about that.” You jumped up as you realized you hadn’t even heard him come in to get you.

“That’s alright,” you waved away his concerns and tried to smile at him. You took his offered hand and he was either stronger than he realized or underestimated how much you weighed because you practically launched off the floor. The momentum made you tumble forward into his chest as he instinctively grabbed you to stop your fall. 

“Sorry!” You yelped. From this close up, his eyes were even more electric, yet they were worried. From the conversation, perhaps? Worried about… Demon’s Blood? As you were processing your thoughts, he brought his lips down to yours for a moment. Before you could snap out of it and kiss him back, he had already pulled away. There was something else in his eyes now - something you couldn’t read. Hurt? Confusion? You stood, still frozen, even after he had let you go. 

“You can rest, if you’d like,” he offered, already walking back out, leaving you to wonder if you’d upset him. Trying to collect yourself for a few minutes, you slowly made your way back to him. For some reason, it hurt that he didn’t even look up at you, even as you made your way to stand behind him. His shoulders were stiff as always, but didn’t seem to relax much this time. 

“Thank you, for catching me,” you said softly in his ear, hands continuing their work. You kissed him gently on the cheek, trying to fix whatever had just transpired. He loosened up slightly at that, though still didn’t say anything. He merely looked back at you and nodded once before turning back to his work. He rolled his shoulders and neck, and let you continue your massage. Feeling bolder, you slid your hands down his arms, feeling muscle underneath the layers of clothing. His back was hard - or tense - it was hard to tell. By the time it was time to go, he let out a soft sigh, which pleased you. Your hands ached a bit, but it was worth it to see his features calmed and serene. You’d make it up next time - if there was a next time.


End file.
